Draft gear



M. E. HALL 2,023,922

DRAFT GEAR Filed May 1, 1953 Patented Dec. 10, 1935 Unirse l'srrx'rss PATENT OFFIQE Marchand B; Hall, Chicago, Ill., assigner to Gardwell-Westinghouse Compan fChicago, Ill., a corporation oflDelaware .-,1 Application May 1, 1933, Serial No. 668,685

2 Qlaims.

This for railway cars.

One of the objects of the-inventionis the provisionof anew and improved draft gear having a novel arrangement of friction elements.

A further-object of theinvention is the provision of a new and improved draft gear having a novel arrangement of the friction elements and .of-the means for'limiting the expansion of the gear.

A still further object of th-e -invention is the provision of a new and improved draft gear having .a novel arrangement of the engaging surfaces of the friction elements.

Another object of thev invention is the provision of a new and improved draft gear that is simple in construction, eicient in operation, inw in the construction of friction draft gears, considerablefdiiculty has been experienced in ob- V.taining a gearrthat has suflicient capacity and `which will releasesmoothlyv and promptly. When the gear is designed to' have a prompt and suitable release, it is often of low capacity and viceversa. The present invention seeks to remedy this diiculty by thefprovision of a construction that has the desired release and in which the capacity may be varied within wide limits by chang-` ing the angles of the friction surfaces of certainl of the elements. v

:Referring now tosthe drawing, the reference y character i5.) designates generally the shock absorber or draft gear which is adapted to be located between the center sills II and I2 of a railway car and between a pair of follower blocks I3 and Mi, as is usual in such constructions. The block I3 may be omitted if desired.

The gear comprises the front follower member l 5 and the rear follower member it. Preferably, these members are hollow and have their adjacent side edges turned outwardly to form the flanges Il, I8, IB and 2|. The flanges I'I and I8 invention relates to shock absorbing. .Y mechanism, and, more particularly, to draft gears (Cl. 21S- 26) on the follower member I5 are provided on the inner surface with inclined wedge faces 22 and 23 and the flanges I 9 and 2i are provided with similar wedge-faces 2d and 25, which are adapted to frictionally engage a` suitable wedge mechanism. This mechanism comprises a pair of wedge members 26 and 2l at each side of the gear. The wedge member 25 has outwardly converging inclined faces 23 and 29 on its outer side parallel with and engaging the friction surfaces 22 and 24,respectively. vThe wedge member 2l is likewise-provided with similar outwardly converging e wedge faces 3| and 32 which are parallel with and frictionally engage the wedging faces 23 and 25 of the followers I5 and I6, respectively.l

Suitable means are provided for frictionally engaging the Wedge members 26 and 2l on their inner surfaces. In the form of construction selected toillustrate one embodiment of the-invention, the wedge member 25 is provided with inwardly converging wedge faces 33 and 34 which are adapted to be engaged by corresponding wedge faces 35 and 36 of a pair of reversely arranged wedge elements 3l and 33. The wedge elements 3l and 38 have wedge faces 3s and 4I corresponding to the wedge faces 35 and 3d. The wedge faces 33 and lil of these elements are adapted to frictionally engage corresponding wedge faces s2 and 43 on the inner side of the wedge member 2l.

Suitable means are provided for resisting the relative movement of the casing and wedge elements and for restoring the parts to normal position after release. Asshovm, the wedge elements 3l and 33 are provided with aligned openf?, l ings extending longitudinally of the gear and a bolt lextends through said axial openings. The bolt preferably, though not necessarily, has a conical head 45 on its forward end which is adapted to seat in a. corresponding recess I5 in e the Vbase of the wedge elements 3l whereby the bolt head will not extend outwardly beyond the `forwardend of the wedge element 3l,

The rear endof the bolt 4t is provided with a spring seat flea secured to the same in any suitable manner,

as by being threaded thereon. Suitable spring means designated generally by the reference character i60, is interposed between the base of the wedge element 3S and the spring seat 45a. This means may comprise onel or more springs. As shown, three springs il, i8 and 49 are employed, the same being arranged concentrically on the bolt or rod 44 in order to secure the maximum spring resistance for the space available for such springs.

Suitable means are provided for limiting the separation of the two follower members l and In the form of construction shown, the flanges l and il are provided with aligned open ings through which a headed bolt 5I extends. This bolt is provided with the usual nut and is of such length that it will permit the follower members to separate a predetermined distance apart. The flanges 8 and El are similarly provided with aligned openings through which a bolt 52 similar to the bolt 5l is inserted.

The wedge members 2S and 2 are provided with grooves 53 and 513, respectively, on their outer portions for providing suicient clearances for the bolts 5I and 52 when the gear is released, as clearly shown in Figs. 1 and 3 of the drawing. Likewise the inner portions of these wedge members are provided with grooves 55 and 56 for receiving the bolt dll when the gear is compressed. The compression of the gear is limited by the contact of the inner ends of the casings 5E and it.

In constructing the gear, the angles formed by the wedge faces .22 and 2d of the wedge member 25 and the corresponding angle formed by the wedge faces 3l and of the wedge Ymembers 2? are determined or calculated so that the gear will have the proper release and will not stick on its releasing movement. The angle must necessarily greater than the angle of repose.

The capacity of the gear is determined largely by the angies formed by the inner faces of the wedge members and 2 and those of the coo erating wedge elements 3l' and By making the angle formed by the faces of the wedge elements 37 and more acute, the higher the capacity of the gear, other things being equal. The size and strength of the spring is also a factor in determining the gear capacity. With the ever increasing size or" cars, it is necessary that the gear be of very high capacity. Usually, the maximum sprin resistance consistent with the dimension of the pocket within which the same is housed is employed. The capacity then will be determined by the angles of the cooperating wedge faces on the wedge elements 37 and 38 and those on the wedge members and 21.

In the operation of the device, a buff of the gear by the drawbar E? will seat the gear against the bufring lugs i3 on the center sills ll and E2` if of sufficient force, will cause the casing i5 to move rearwardly. Likewise, a pull on the drawbar will cause the yoke 59, attached thereto and encircling the gear, to seat gear against the draft lugs 6i, and, if of sufiicient force, will cause the casing 53 to move forwardly, thereby wedging the wedge members 23 2l inwardly which in turn will separate the wedge elements and 3S against the compression of the springs and 9.

It will thus be seen that the less acute the angles formed by the wedge faces of the wedge elements 3i and 38, the more easily'these elements are forced apart by the wedge members and hence the less capacity the gear possesses, and the more acute the angles, the greater the capacity of the gear.

It Will be noted that with a given angle for the outer wedge faces of the wedge members 26 5 and 2'?, the travel of the wedge elements 3'.' and 38 must necessarily be confined to certain limits because of the size of the gear pocket and that this travel will vary as the angle formed by the.l wedge faces of the Wedge elements 31 and 38,10 and this, in turn, will affect the length of the springsthat may be used. The gear capacity is preferably varied by changing the angle of the wedge elements, but may be varied within limits by changing the size or nature of the spring resistance.

I claim as my invention:

1. A draft gear for use in the draft gear pocket of a railway car comprising a pair of casings,- each' having anges on its ends terminating ad- 20 jacent to the side walls of said pocket, one of said casings being tubular and open at both ends, bolts extending through the anges on adjacent ends of said casings for limiting the separation of said casings, inclined frictional surfaces on said anges and the inner ends of said casings, blocks having wedging faces engaging said friction surfaces, wedge members engaging said blocks, a bolt element extending through said members, a cap on said last named bolt element of slightly :V1.0 less diameter than the interior of the tubular casing and constituting a closure for said lastnamed casing, and spring means on said bolt interposed between said cap and one of said wedge members, and constituting the sole resilient Y' means for resisting the separation of said Wedge members, said blocks having recesses on opposite portions thereof for receiving said bolts whereby the friction surfaces thereon are greatly increased in area. 40

2. In a draft gear, a pair of follower casings, flanges on opposite sides of the adjacent ends of said casings, said flanges being adapted to engage for limiting the compression of the gear, the adjacent ends of said casings and adjacent anges being provided with inclined wedging faces, bolts extending through the ,adjacent flanges of said casings for limiting the separation of said casings, a pair of wedge blocks engaging said wedging faces, a pair of wedge members engaging said wedge blocks, a bolt extending through said wedge members and having its head in engagement with one of them, a cap on the other end of said last-named bolt of slightly less diameter than the interior diameter of the casing 65 whereby said bolt will prevent skewing of said block and wedge elements, and a spring between said cap and said wedge members, the exteriorsurface of said spring being separated from the top and bottom walls of said casing within which said spring is contained only a suflicient distance to afford proper clearance for operation.

MARCHAND B. HALL. 

